Apparatus for cracking hydrocarbon oils to produce light oils



Feb. 27, 1934. G, EGLoFF ET AL APPARATUS FOR CRACKING HYDROCARBON OILS TO PRODUCE LIGHT OILS Original Filed June 28. 1920 A TTOR NE Y.

Patented Feb. 27, 1934 UNITED STATES APPARATUS FOR CRACKING HYDROCAR- BON OILS TO PRODUCE LIGHT OILS Gustav Egloff and Harry P. Benner, Chicago, Ill., assignors to Universal Oil Products Company, Chicago, Ill., a corporation of South Dakota Original application June 28, 1920, Serial No. 392,475. Divided and this application March 6 Claims.

This application is a division of our application Serial No. 392,475, filed June 28, 1920, now Patent No. 1,710,153.

Our invention relates to an apparatus for cracking heavy hydrocarbon oils by means of heat and pressure, `in a double high pressure still, and means of internally heating same for the production of light oils characteristically gasoline or the like.

`Its salient objects are to provide a pressure distillation apparatus for cracking heavy hydrocarbon oils to produce light oils therefrom; to provide an apparatus which may be operated continuously for the pressure distillation of heavy hydrocarbon oils to produce light oils therefrom by means of a combustion chamber set within the body of the double high pressure still; to provide an apparatus for the pressure distillation of heavy hydrocarbon oils to produce light oils therefrom by means of a double high pressure still and superheating the hydrocarbon vapors generated by one of said double high pressure stills; to provide a pressure distillation apparatus for the hydrocarbon oils to produce light oils, such as 'gasoline or the like, from said heavy hydrocarbon oils by means of charging the lower of the double high pressure stills and spraying untreated oil continuously over said oil while on pressure distillation; to provide an apparatus for the pressure distillation of heavy hydrocarbon oils to produce light oils therefrom by means of a double high pressure still in which both stills of said double high pressure still are charged 3 with said hydrocarbon oil to be treated, and continuously charging untreated oil to the syste during pressure distillation.

The following is a description of an apparatus as shown in the drawing. 4 The numeral 1 represents a gas burner set in corrugated tube 2, which is within high pressure still 6. 2--a is a connection between corrugated tube 2 and corrugated tube 3 set in pressure still 5, to which tube 3 stack 4 is attached. `A vapor line 7 connects pressure still 5 through valve 8, and pipe 9 to dephlegmator 10 having bale plates l1 set therein and provided with an inverted dish 12, and dephlegmated oil trap 13. The numeral 13a, designates a dephlegmated oil or reflux return pipe attached to the ,lower part of still 6. The numeral 14 designates a. vapor conduit connected with dephlegmator 10 in which conduit is placed valve 15. The pipe extension 15-a leads to condenser coil 16, setwithin water condenser box 17. The condensed pressure distillate oil passing through pipe 18 with uncondensable gas from condenser Serial No. 174,445

coil 16 passes to receiver 19. Pipe 20 is attached to receiver 19 with pressure distillatecontrol valve 21, having pipe 21--a connected with storage tank for pressure distillate oil. Pipe 23 is uncondensable gas line controlled by valve 22. Pipe 22-a is connected to uncondensable gas tank. The numeral 24 represents pressure gage, and number 24-a the gauge glass upon receiver 19. A raw oil pump 25 pumps raw oil via valve 26 and discharges through control valve 27 through preheater coil 28. A control valve 27 is used for passing raw oil through preheater coil 28 set in the path of combustion gases in flue 2-a. The preheated raw oil from coil 28 passes through pipe 29 set in still 6, having perforations 30, through which the oil sprays into said still 6. The numeral 6-a represents pipes which connect still 6 with still 5, being projected above the bottom of still 5. Insulating material 5-a surrounds stills 5 and 6. Number 31 is'draw off pipe for residuum from still 6, controlled by valve 32, attached to pipe connection 33 with storage tank for said residuum oil.

One typical method of operation of this process and apparatus when cracking a very refractory oil, such as steam still kerosene bottoms, Pine Island gas oil and the like, is to charge still 6 with one of said oils by means of raw oil pump 25, through coil 28 and pipe 29, or still 6 may be charged by way of residuum` line 31, connected with valve 32 and pipe connections 33 by means of pump not shown. The pressure distillate control valve 21 and uncondensable gas valve 22 are closed. Valve 8 and 15 are opened. Burner 1 is ignited, the products of combustion passing corrugated tube 2, connection 2-a attached to corrugated tube 3, set in still 5, passing out of stack 4. `The hydrocarbon vapors generated in the system produce a generated pressure upon the entire system which is predetermined dependent upon the type oil used. As the desired self-impressed pressure has been created in the system the operation may be continued under such pressure by suitably controlling the throttle valves 21 and 22 on the receiver 19. The hydrocarbon vapors generated in still 6 passing through pipes 6-a, connected to still 5 are superheated by the products of combustion, passing through corrugated tube 3. The hydrocarbon vapors from still 5, passing through pipe 7, valve 8 and pipe 9, attached to dephlegmator 16 are fractionated, so that only the lighter vapors pass out through conduit 14, valve 15 and pipe 15a to be condensed in condenser coil 16, running into receiver 19 when the system is on pressure distillation. The dephlegmated liquid condensed in fdephlegmator 10 drops back in said dephlegmator to the trap 13, passing down through pipe `connections l-a, to the lower part of still 6. It is important to note in this pressure distillation process and apparatus that we do away entirely with furnace construction of brick work or like material. We also do away with high furnace box construction which necessitates all construction work on pressure distillation apparatus being built 8 or 10 feet higher than `our apparatus. We have found that this cuts down the construction costs markedly and is an important feature of our apparatus. Our apparatus also economizes upon fuel consumption, as the products of combustion, pass through 'the internal part of the still so that we do away with radiating heat from furnace walls and reduce heat loss to a minimum. Our stills are heavily insulated with magnesia brick or kieselguhr. It is to be noted that the products of combustion within the lower still pass on after giving up part of its heat content to the liquid in said lower still and superheat the vapors in upper still, which then pass out through the dephlegmator. We also have found that by preheating the raw oil fed into the system by means of waste products of combustion, that the capacity of the stills is increased.

A typical operating run was to distil a Pine Island gas oil of 31.0 Baume gravity at a pressure of 125 pounds, producing therefrom 60 per cent of a pressure distillate oil of 51.0 Baume gravity containingr therein 55 percent of a 57-58 Baume gravity gasoline. This yielded 33 per cent of 5'7-58 Baume gravity gasoline on the basis of oil used.

The above is the preferred method of operation of this apparatus. However, when using easily crackable oils, such as fuel oils, heavy residuuins, heavy crude oils we may charge both stills with one of said oils and spray in raw charging oil into the upper still instead of the lower.

We do not limit ourselves to any particular amount of still charge, because this is determined by the type oil which is to be cracked in our process. Nor does the type dephlegmator upon the system as shown in drawing, act advantageously on all hydrocarbon oils. We have found that the character of the hydrocarbon oils profoundly modifies the type of dephlegmating system necessary for cracking commercially.

We do not limit ourselves in this process to horizontal type stills but may utilize and believe it is within our disclosure to operate vertical and tube still arrangement.

We claim as our invention:

1. An apparatus for cracking petroleum oil in combination with an elongated heating element, through which gases of combustion are adapted to pass, of a spraying device, adapted to deliver oil in the form of a spray over the exterior surface of said heating element, means for delivering oil, under relatively high velocity and pressure, to said spray, including means for passing the oil through a closed preheating coil prior to passage to said spray, and means for taking off generated vapors and subjecting. them to condensing action.

2. In combination with a conduit, through which combustion gases progressively advance, of a closed coil of restricted cross-sectional area, positioned in the direct path of the combustion gases advancing through said conduit, means for supplying oil, under pressure, to said closed coil, and means for spraying oil, subsequent to its passage through said closed coil, over the exterior of said conduit.

3. In combination with a conduit, through which combustion gases progressively advance, of a closed'coil of restricted cross-sectional area, positioned in the direct path of the combustion gases advancing through said conduit, means for supplying oil, under pressure, to said closed coil and means for spraying oil, subsequent to its passage through said closed coil, over the exterior of said conduit, means for initially introducing the combustion gases to that portion of the conduit over which the oil is sprayed, whereby the highest heat is imparted to the oil passing over the exterior of said conduit.

4. Apparatus for cracking hydrocarbon oil comprising in combination, means for preheating the charging oil, a cracking chamber, a cylindrical heating surface in said chamber, means for spraying the preheated charging oil over said surface whereby vapors are evolved from said oil, a second chamber, means for passing the evolved vapors from the cracking chamber to the second chamber, a dephlegmator, means for passing the vapors from said second chamber to said dephlegmator, means for returning reflux condensate from the dephlegmator to the cracking chamber, means for condensing and collecting the vapors uncondensed by said dephlegmator, and means for passing gases of combustion through the apparatus to heat the cylindrical surface, the preheating means and the second chamber in the order set forth.

5. Apparatus for cracking hydrocarbon oil comprising in combination, means for preheating the charging oil, a cracking chamber, a cylindrical heating surface in said chamber, means for spraying the preheated charging oil over said surface whereby vapors are evolved from said oil, a second chamber, means for passing the evolved vapors from the cracking chamber to the second chamber, a dephlegmator, means for passing the vapors from said second chamber to said dephlegmator, means for returning reflux condensate from the dephlegmator to the cracking chamber, means for condensing and collecting the vapors uncondensed by said dephlegmator, and means for passing gases of combustion through the apparatus to heat the cylindrical surface, the preheating means and the second chamber in the order set forth comprising an elongated conduit through which Said gases pass, said conduit passing successively through said cracking chamber and second chamber and having an enlarged intermediate portion receiving the preheating means.

6. An apparatus for cracking hydrocarbon oil comprising a heating coil and means for passing oil therethrough, an enlarged chamber and means for discharging the oil thereinto from the coil for separation intov vapors and residuum, means for separately removingV vapors and residuum from said chamber, a second chamber and means for transferring vapors thereto from the first mentioned chamber, means for passing combustion gases over said coil to heat the oil passing therethrough and thence internally through said second chamber in heat exchange relation but out of contact with the vapors therein, and

means for removing the vapors from said second chamber.

GUSTAV EGLOFF. HARRY P. BENNER, 

